C6-Chemical synthesis

HideShow resource information
  • Created by: Naana
  • Created on: 30-05-14 13:32
Give an example of one chemical that is produced on a small scale and one chemical that is produced on a large scale
Sulphuric acid=large scale, pharmaceuticals=smaller scale
1 of 30
Give an example of a pure acidic compound that is a liquid
Nitric acid
2 of 30
What 3 ways can you measure the pH of a substance?
Litmus paper turns red if the solution is acidic and blue if the solution is alkaline. Universal indicator is a combo of dyes which gives the pH colours. pH metres is made up of a probe which is dipped into a substance and a meter which reads the pH.
3 of 30
What is an acid?
It is a substance with a pH of less than 7. Acidic compounds produce aqueous hydrogen ions (H+) in water
4 of 30
What is an alkaline?
It is a substance with a pH greater than 7. Alkaline compounds produce aqueous hydroxide ions (OH-) in water
5 of 30
What does an acid and alkaline react to form?
Salt and water (neutralisation reaction)
6 of 30
What does an acid and metal react to form?
Salt and hydrogen
7 of 30
What will hydrochloric acid when reacted with metal always produce?
It will always produce chloride salts e.g. magnesium chloride, aluminium chloride, zinc chloride
8 of 30
What will sulphuric acid when reacted with metals always produce?
It will always produce sulphate salts e.g. magnesium sulphate, aluminium sulphate, zinc sulphate
9 of 30
What do metal oxides and hydroxides react with acids to form?
Salt and water (neutralisation reaction)
10 of 30
What does an acid and metal carbonates react to form?
Salt, water and carbon dioxide
11 of 30
What are the seven steps involved in the chemical synthesis?
Choosing the reaction, risk assessment, calculating the quantities of reactants, choosing the apparatus and conditions, isolating the product, purification and measuring yield and purity
12 of 30
What is involved in carrying out a risk assessment?
Identifying hazards, assessing who may be harmed and deciding what action can be taken to reduce the risk.
13 of 30
Why is it important to choose the right apparatus for a chemical process?
Because the apparatus needs to be the correct size for the amount of products and reactants, and strength for the type of reaction being carried out
14 of 30
What does calculating the yield tell you about a reaction?
It tells you about the overall success of the process. It compares what you think you should get with what you actually get.
15 of 30
What are filtrations used for?
They are used to separate an insoluble solid product from a liquid. It can also be used in purification as well, to separate the solid impurities in the reaction mixtures.
16 of 30
What are evaporation and crystallisation used for?
They are used to separate soluble solids from a solution. When the solute is evaporated the solid crystals of the product are left behind. And because the crystals have a regular structure, impurities can’t fit in-useful for purification
17 of 30
Give 2 methods used to dry a product
A drying oven-heat or blow hot dry air over product. A desiccators are containers that contain chemicals like silica gel that remove water and help keep product dry.
18 of 30
What is the formula for percentage yield?
Actual yield (grams)/theoretical yield (grams) ×100
19 of 30
Describe how to carry out a titration
Add known volume of alkali to a titration flask, with two drops of indicator. Fill a burette with acid; add acid to alkali mixture in drops and mix. Indicator changes colour when all the alkali has been neutralised, record the volume of acid used
20 of 30
What are titrations used for?
To check and measure the purity of acidic or alkaline products
21 of 30
Why is purification of a product important?
In pharmaceuticals production, drugs made for humans need to be free from impurities so they don’t do more harm than good. In petrochemicals production, petrol products need to be free from impurities/contamination so they don’t damage the car’s engi
22 of 30
What is an exothermic reaction?
This is a reaction which gives out energy to its surroundings, usually in the form of heat and is shown by a rise in temperature.
23 of 30
What is an endothermic reaction?
This is a reaction which takes in energy from its surroundings, usually in the form of heat and is shown by a fall in temperature.
24 of 30
Give 2 reasons why it is important to control the rate of a chemical reaction in industry
For safety reasons-if the reaction is too fast it could cause an explosion which is dangerous. For economic reasons- changing the conditions can be costly
25 of 30
What 4 things affect the rate of reaction?
Temperature, concentration, presence of catalyst and surface area (size of solid particles)
26 of 30
What is the formula for calculating the rate of reaction?
Amount of reactant used or amount of products formed/time
27 of 30
How is the precipitate and colour change used to measure the rate of reaction?
You can time how long it takes for the reactant to gain/ lose its colour if the product of the reaction is coloured/ colourless. You can also time how long it takes for a precipitate to form if the product is a precipitate which clouds the solution.
28 of 30
How is the change of mass used to measure the rate of reaction?
As the gas is released the mass disappearing is easily measured on the balance. The quicker the reading on the balance drops, the faster the reaction.
29 of 30
How is the volume of gas given off is used to measure the rate of reaction?
This involves using a gas syringe to measure the volume of gas given off. The more gas given off during a given time interval, the faster the reaction.
30 of 30

Other cards in this set

Card 2

Front

Give an example of a pure acidic compound that is a liquid

Back

Nitric acid

Card 3

Front

What 3 ways can you measure the pH of a substance?

Back

Preview of the front of card 3

Card 4

Front

What is an acid?

Back

Preview of the front of card 4

Card 5

Front

What is an alkaline?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Rate of reaction resources »